1. Field of the Invention
The present invention relates to an implantable drug delivery device for infusing a therapeutic agent into an organism, and more particularly, relates to an improved peristaltic implantable pump using tube guides for improved alignment of a fluid tube.
2. Description of the Related Art
Implantable drug infusion devices are well known in the art. These devices typically include a medication reservoir within a generally cylindrical housing. Some form of fluid flow control is also provided to control or regulate the flow of fluid medication from the reservoir to the outlet of the device for delivery of the medication to the desired location in a body, usually through a catheter. These devices are used to provide patients with a prolonged dosage or infusion of a drug or other therapeutic agent.
Active drug infusion devices feature a pump or a metering system to deliver the drug into the patient""s system. An example of such a drug infusion pump currently available is the Medtronic SynchroMed programmable pump. Additionally, U.S. Pat. Nos. 4,692,147 (Duggan), 5,840,069 (Robinson), and 6,036,459 (Robinson), assigned to Medtronic, Inc., Minneapolis, Minn., disclose body-implantable electronic drug administration devices comprising a peristaltic (roller) pump for metering a measured amount of drug in response to an electronic pulse generated by control circuitry associated within the device. Each of these patents is incorporated herein by reference in their entirety for all purposes. Such pumps typically include a drug reservoir, a fill port, a peristaltic pump having a motor and a pumphead to pump out the drug from the reservoir, and a catheter port to transport the drug from the reservoir via the pump to a patient""s anatomy. The drug reservoir, fill port, peristaltic pump, and catheter port are generally held in a housing, or bulkhead. The bulkhead typically has a series of passages extending from the drug reservoir and through the peristaltic pump that lead to the catheter port, which is typically located on the side of the housing. The peristaltic pumps use rollers which move along a pump tube, thereby moving liquid through the tube.
The prior art delivery devices, however, are limiting in that the tube may not be properly aligned with respect to the rollers, leading to inefficient occlusion of the tube. Prior art solutions to the alignment problem include placing wings along the tube, which may lead to an increased height of the device, compromise the tubing geometry, and increase the cost and complexity of manufacture of the tube.
It is an object of the present invention to provide an implantable drug infusion device which reduces or wholly overcomes some or all of the difficulties inherent in prior known devices. Particular objects and advantages of the invention will be apparent to those skilled in the art, that is, those who are knowledgeable or experienced in this field of technology, in view of the following disclosure of the invention and detailed description of preferred embodiments.
The present invention provides an implantable drug infusion device which features a peristaltic pump having a new configuration, in which a roller assembly of the peristaltic pump includes a tube guide to properly align a pump tube with respect to rollers of the roller assembly.
In accordance with a first aspect, an implantable drug infusion device includes an implantable drug infusion device including a pump tube for holding a liquid to be pumped. A race is configured to support the tube along a path. A roller assembly is configured to compress the tube against the race at one or more points along the path, and the roller assembly includes at least one roller. At least one tube guide is operably connected to the roller assembly to align the pump tube with respect to a corresponding roller.
In accordance with another aspect, an implantable drug infusion device includes a bulkhead having a race. A pump tube having an inlet and an outlet is positioned within the race. A roller assembly is configured to compress the tube against the race at at least one point along the path, and the roller assembly includes at least one roller. A drive assembly drives the roller assembly relative to the tube along the path so as to move a liquid through the tube. At least one tube guide is operably connected to the roller assembly to align the pump tube with respect to a corresponding roller.
From the foregoing disclosure, it will be readily apparent to those skilled in the art, that is, those who are knowledgeable or experienced in this area of technology, that the present invention provides a significant advance over the prior art. Preferred embodiments of the implantable infusion device of the present invention can significantly improve the alignment of a pump tube with rollers of the device. This will allow for increased manufacturing flexibility, decreased cost of tube manufacture, reduced height of the device, and improved performance. These and additional features and advantages of the invention disclosed here will be further understood from the following detailed disclosure of preferred embodiments.